Marvelous Mechanisms: The Ubiquitous Four Bar Linkage
The four bar linkage is a type of mechanical linkage that is used in many different devices. A few examples are: locking pliers, bicycles, oil well pumps, loaders, internal combustion engines, compressors, and pantographs. In biology we can also find examples of this linkage, as in the human knee joint, where the mechanism allows rotation and keeps the two legs bones attached to each other. It is also present in some fish jaws that evolved to take advantage of the force multiplication that the four bar mechanism can provide.
How It Works
The study of linkages started with Archimedes who …read more
Source Parts on TaoBao: An Insider’s Guide
For hardware aficionados and Makers, trips to Shenzhen’s Huaqiangbei have become something of a pilgrimage. While Huaqiangbei is a tremendous and still active resource, increasingly both Chinese and foreign hardware developers do their sourcing for components on TaoBao. The selection is vastly greater and with delivery times rarely over 48 hours and frequently under 24 hours for local purchases it fits in nicely with the high-speed pace of Shenzhen’s hardware ecosystem.
For overseas buyers, while the cost of Taobao is comparable to, or slightly less than AliExpress and Chinese online stores, the selection is again, many, many times the size. …read more
Hacked IoT Switch Gains I2C Super Powers
Economies of scale and mass production bring us tons of stuff for not much money. And sometimes, that stuff is hackable. Case in point: the $5 Sonoff WiFi Smart Switch has an ESP8266 inside but the firmware isn’t very flexible. The device is equipped with the bare minimum 1 MB of SPI flash memory. Even worse, it doesn’t have
the I2C ports extra pins exposed so that you can’t just connect up your own sensors and make them much more than just a switch. But that’s why we have soldering irons, right? …read more
Getting Sparks from Water with Lord Kelvin’s Thunderstorm
In the comments to our recent article about Wimshurst machines, we saw that some hackers had never heard of them, reminding us that we all have different backgrounds and much to share. Well here’s one I’m guessing even fewer will have heard of. It’s never even shown up in a single Hackaday article, something that was also pointed out in a comment to that Wimshurst article. It is the Lord Kelvin’s Water Dropper aka Lord Kelvin’s Thunderstorm, invented in the 1860s by William Thomson, 1st Baron Kelvin, the same fellow for whom the Kelvin temperature scale is named. It’s a …read more
Low Background Steel — So Hot Right Now
The nuclear age changed steel, and for decades we had to pay the price for it. The first tests of the atomic bomb were a milestone in many ways, and have left a mark in history and in the surface of the Earth. The level of background radiation in the air increased, and this had an effect on the production of steel, so that steel produced since 1945 has had elevated levels of radioactivity. This can be a problem for sensitive instruments, so there was a demand for steel called low background steel, which was made before the trinity tests. …read more